Yamaha CS20M

It is a mono synthesizer in the late 70s, 3 octaves, 2 and VCO 1 LFO.Il has the distinction of having eight memory controlled by big square buttons easily accessible, nothing to do with the small switches 2 bullets found now. Note that there is a cassette interface to safeguard its presets.
The design is beautiful, there is room, no excessive miniaturization, everything is clear and tidy. The fact that manufacturing is not small, it's solid, but strong like a tank.
Its strong point is to have a section of very full expression to the left of the keyboard settings: two wheels pitch bend / modulation of the classic but with the possibility to select the range of action of the pitch bend. Awesome. It also has access to the cutoff frequency of the filter, and sustain.

UTILIZATION

Usage is very simple, no need to even the doc, pure happiness. It lights up, it was sound, no boot, no click, no mouse, no password, nirvana ...
Technological limitations of the time is that you can not edit a sound memory. We must be sure that the sound was created before storing. After more way to edit (except with the expression left settings) except by putting all the settings in the same position and the remémorisant. Hence the interest of a photo of the front panel when you have found the sound that kills ....

SOUNDS

We can make beautiful leads, which can be quite aggressive for analog sounds are very clear, especially the bass ... the secret lies in the ability to inject a sine wave generated by the VCO1 in the VCA. And there was low while taking off ....
You can also make effects, although it is not its primary purpose.
There are plenty of modulation possibilities, particularly a positive or negative glide (adjustable length).
The multimode filter (low-pass, band-pass, high-pass), but is not self-oscillating. However, it may be well with biting resonance max. Not annoying to me.
Also very interesting the possibility to multiply by five the duration of envelopes ... very very good! attacks are very fast, which increases the edgier side leads
Nothing to say, the beautiful analog sound in the tradition of legendary CS-80 (this is exactly the same circuits that are used in the CS-20M).

OVERALL OPINION

An instrument of this quality is priceless. Warning only if there are failures, Yamaha circuits are very difficult (if not impossible) to find on the market. So test everything before buying!

A small mono synth (either by size or by the weight !!!).
2 VCO, 1 LFO, 1 gnrateur white noise, a multi-mode filter, 2 ADSR.
Programmable, with 8 memory backup on tape (!)
Programs once records are no longer ditables except some rglages (white button)
Connectivity complte, output jack or XLR, volume pedals, sustain, portamento, headphone, CV, cassette
Of CONTRL "left hand" complete: 1 pitch bend, a modulation, a sustain (which lengthens the ADSR), a brightness (vcf cutoff freq), a portamento

UTILIZATION

Simple to use! is the strength of the unit. Good design, good ergonomics. A control panel trs clear, even didactic. Orders "left hand" trs sympathetic. With a little finger you can play the filter, the bend, portamento, etc ... while at the same time. A synthetic anti-making head! ...
Its eight programs (the interface with infinite tape!) And its ease of use make a synth for live IDAL.

SOUNDS

This is an analog sound is trs typ. The envelopes are nergiques ... it's good for leads. A tip: in a sub-tilt sinusode to round the sound in the bass ... it's good for the bass.
The multi-mode filter can vary the sound and make sounds thinner than a low-pass.
The filter can be pretty sweet ... sounds like "brass" going well.
In short, good versatility.

OVERALL OPINION

Conclusion: This my first synth ft (not Fisher-Price!) There are a couple of decades, and he is discovering the joys of synthse. Today, having spent the APRS numrique, I always use. Even if it's not a synth trs it marks the cot cot a Difference numrique (the legendary warmth of analog ...).
And I like Yamaha ... It's tough! Never fails. And, with it's rare in this age bx l. I also have a DX7 ... same ... indestructible! Neither one nor the other are selling.